Take any 2012 team, use baseballreference.com for players (team members must have had at least one PA in 2012). You may use either partial or full seasons for traded players. Once teams are set, they will be aligned based on order of finish to keep it a little more even. Here is the twist. Based on winning percentage rank (1-24), you get a certain number of twists to any season of the player's career.
See below for the twists for each team. This will be a 24-team league.

THE RULES
80 mil cap
No ww or trades
Injuries on
AAA 6-2 (above average - you pick 'em)
No DH (I'm an NL purist, but will change if enough AL owners ask)
Use actual team stadium